1 /*
2 * Copyright (c) 2023, 2025, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "cds/aotMappedHeapLoader.hpp"
26 #include "cds/aotMappedHeapWriter.hpp"
27 #include "cds/aotReferenceObjSupport.hpp"
28 #include "cds/cdsConfig.hpp"
29 #include "cds/filemap.hpp"
30 #include "cds/heapShared.inline.hpp"
31 #include "cds/regeneratedClasses.hpp"
32 #include "classfile/javaClasses.hpp"
33 #include "classfile/modules.hpp"
34 #include "classfile/systemDictionary.hpp"
35 #include "gc/shared/collectedHeap.hpp"
36 #include "memory/allocation.inline.hpp"
37 #include "memory/iterator.inline.hpp"
38 #include "memory/oopFactory.hpp"
39 #include "memory/universe.hpp"
40 #include "oops/compressedOops.hpp"
41 #include "oops/objArrayOop.inline.hpp"
42 #include "oops/oop.inline.hpp"
43 #include "oops/oopHandle.inline.hpp"
44 #include "oops/typeArrayKlass.hpp"
45 #include "oops/typeArrayOop.hpp"
46 #include "runtime/java.hpp"
47 #include "runtime/mutexLocker.hpp"
48 #include "utilities/bitMap.inline.hpp"
49 #if INCLUDE_G1GC
50 #include "gc/g1/g1CollectedHeap.hpp"
51 #include "gc/g1/g1HeapRegion.hpp"
52 #endif
53
54 #if INCLUDE_CDS_JAVA_HEAP
55
56 GrowableArrayCHeap<u1, mtClassShared>* AOTMappedHeapWriter::_buffer = nullptr;
57
58 // The following are offsets from buffer_bottom()
59 size_t AOTMappedHeapWriter::_buffer_used;
60
61 // Heap root segments
62 HeapRootSegments AOTMappedHeapWriter::_heap_root_segments;
63
64 address AOTMappedHeapWriter::_requested_bottom;
65 address AOTMappedHeapWriter::_requested_top;
66
67 GrowableArrayCHeap<AOTMappedHeapWriter::NativePointerInfo, mtClassShared>* AOTMappedHeapWriter::_native_pointers;
68 GrowableArrayCHeap<oop, mtClassShared>* AOTMappedHeapWriter::_source_objs;
69 GrowableArrayCHeap<AOTMappedHeapWriter::HeapObjOrder, mtClassShared>* AOTMappedHeapWriter::_source_objs_order;
70
71 AOTMappedHeapWriter::BufferOffsetToSourceObjectTable*
72 AOTMappedHeapWriter::_buffer_offset_to_source_obj_table = nullptr;
73
74 DumpedInternedStrings *AOTMappedHeapWriter::_dumped_interned_strings = nullptr;
75
76 typedef HashTable<
77 size_t, // offset of a filler from ArchiveHeapWriter::buffer_bottom()
78 size_t, // size of this filler (in bytes)
79 127, // prime number
80 AnyObj::C_HEAP,
81 mtClassShared> FillersTable;
82 static FillersTable* _fillers;
83 static int _num_native_ptrs = 0;
84
85 void AOTMappedHeapWriter::init() {
86 if (CDSConfig::is_dumping_heap()) {
87 Universe::heap()->collect(GCCause::_java_lang_system_gc);
88
89 _buffer_offset_to_source_obj_table = new BufferOffsetToSourceObjectTable(/*size (prime)*/36137, /*max size*/1 * M);
90 _dumped_interned_strings = new (mtClass)DumpedInternedStrings(INITIAL_TABLE_SIZE, MAX_TABLE_SIZE);
91 _fillers = new FillersTable();
92 _requested_bottom = nullptr;
93 _requested_top = nullptr;
94
95 _native_pointers = new GrowableArrayCHeap<NativePointerInfo, mtClassShared>(2048);
96 _source_objs = new GrowableArrayCHeap<oop, mtClassShared>(10000);
97
98 guarantee(MIN_GC_REGION_ALIGNMENT <= G1HeapRegion::min_region_size_in_words() * HeapWordSize, "must be");
99 }
100 }
101
102 void AOTMappedHeapWriter::delete_tables_with_raw_oops() {
103 delete _source_objs;
104 _source_objs = nullptr;
105
106 delete _dumped_interned_strings;
107 _dumped_interned_strings = nullptr;
108 }
109
110 void AOTMappedHeapWriter::add_source_obj(oop src_obj) {
111 _source_objs->append(src_obj);
112 }
113
114 void AOTMappedHeapWriter::write(GrowableArrayCHeap<oop, mtClassShared>* roots,
115 ArchiveMappedHeapInfo* heap_info) {
116 assert(CDSConfig::is_dumping_heap(), "sanity");
117 allocate_buffer();
118 copy_source_objs_to_buffer(roots);
119 set_requested_address(heap_info);
120 relocate_embedded_oops(roots, heap_info);
121 }
122
123 bool AOTMappedHeapWriter::is_too_large_to_archive(oop o) {
124 return is_too_large_to_archive(o->size());
125 }
126
127 bool AOTMappedHeapWriter::is_string_too_large_to_archive(oop string) {
128 typeArrayOop value = java_lang_String::value_no_keepalive(string);
129 return is_too_large_to_archive(value);
130 }
131
132 bool AOTMappedHeapWriter::is_too_large_to_archive(size_t size) {
133 assert(size > 0, "no zero-size object");
134 assert(size * HeapWordSize > size, "no overflow");
135 static_assert(MIN_GC_REGION_ALIGNMENT > 0, "must be positive");
136
137 size_t byte_size = size * HeapWordSize;
138 if (byte_size > size_t(MIN_GC_REGION_ALIGNMENT)) {
139 return true;
140 } else {
141 return false;
142 }
143 }
144
145 // Keep track of the contents of the archived interned string table. This table
146 // is used only by CDSHeapVerifier.
147 void AOTMappedHeapWriter::add_to_dumped_interned_strings(oop string) {
148 assert_at_safepoint(); // DumpedInternedStrings uses raw oops
149 assert(!is_string_too_large_to_archive(string), "must be");
150 bool created;
151 _dumped_interned_strings->put_if_absent(string, true, &created);
152 if (created) {
153 // Prevent string deduplication from changing the value field to
154 // something not in the archive.
155 java_lang_String::set_deduplication_forbidden(string);
156 _dumped_interned_strings->maybe_grow();
157 }
158 }
159
160 bool AOTMappedHeapWriter::is_dumped_interned_string(oop o) {
161 return _dumped_interned_strings->get(o) != nullptr;
162 }
163
164 // Various lookup functions between source_obj, buffered_obj and requested_obj
165 bool AOTMappedHeapWriter::is_in_requested_range(oop o) {
166 assert(_requested_bottom != nullptr, "do not call before _requested_bottom is initialized");
167 address a = cast_from_oop<address>(o);
168 return (_requested_bottom <= a && a < _requested_top);
169 }
170
171 oop AOTMappedHeapWriter::requested_obj_from_buffer_offset(size_t offset) {
172 oop req_obj = cast_to_oop(_requested_bottom + offset);
173 assert(is_in_requested_range(req_obj), "must be");
174 return req_obj;
175 }
176
177 oop AOTMappedHeapWriter::source_obj_to_requested_obj(oop src_obj) {
178 assert(CDSConfig::is_dumping_heap(), "dump-time only");
179 HeapShared::CachedOopInfo* p = HeapShared::get_cached_oop_info(src_obj);
180 if (p != nullptr) {
181 return requested_obj_from_buffer_offset(p->buffer_offset());
182 } else {
183 return nullptr;
184 }
185 }
186
187 oop AOTMappedHeapWriter::buffered_addr_to_source_obj(address buffered_addr) {
188 OopHandle* oh = _buffer_offset_to_source_obj_table->get(buffered_address_to_offset(buffered_addr));
189 if (oh != nullptr) {
190 return oh->resolve();
191 } else {
192 return nullptr;
193 }
194 }
195
196 Klass* AOTMappedHeapWriter::real_klass_of_buffered_oop(address buffered_addr) {
197 oop p = buffered_addr_to_source_obj(buffered_addr);
198 if (p != nullptr) {
199 return p->klass();
200 } else if (get_filler_size_at(buffered_addr) > 0) {
201 return Universe::fillerArrayKlass();
202 } else {
203 // This is one of the root segments
204 return Universe::objectArrayKlass();
205 }
206 }
207
208 size_t AOTMappedHeapWriter::size_of_buffered_oop(address buffered_addr) {
209 oop p = buffered_addr_to_source_obj(buffered_addr);
210 if (p != nullptr) {
211 return p->size();
212 }
213
214 size_t nbytes = get_filler_size_at(buffered_addr);
215 if (nbytes > 0) {
216 assert((nbytes % BytesPerWord) == 0, "should be aligned");
217 return nbytes / BytesPerWord;
218 }
219
220 address hrs = buffer_bottom();
221 for (size_t seg_idx = 0; seg_idx < _heap_root_segments.count(); seg_idx++) {
222 nbytes = _heap_root_segments.size_in_bytes(seg_idx);
223 if (hrs == buffered_addr) {
224 assert((nbytes % BytesPerWord) == 0, "should be aligned");
225 return nbytes / BytesPerWord;
226 }
227 hrs += nbytes;
228 }
229
230 ShouldNotReachHere();
231 return 0;
232 }
233
234 address AOTMappedHeapWriter::buffered_addr_to_requested_addr(address buffered_addr) {
235 return _requested_bottom + buffered_address_to_offset(buffered_addr);
236 }
237
238 address AOTMappedHeapWriter::requested_address() {
239 assert(_buffer != nullptr, "must be initialized");
240 return _requested_bottom;
241 }
242
243 void AOTMappedHeapWriter::allocate_buffer() {
244 int initial_buffer_size = 100000;
245 _buffer = new GrowableArrayCHeap<u1, mtClassShared>(initial_buffer_size);
246 _buffer_used = 0;
247 ensure_buffer_space(1); // so that buffer_bottom() works
248 }
249
250 void AOTMappedHeapWriter::ensure_buffer_space(size_t min_bytes) {
251 // We usually have very small heaps. If we get a huge one it's probably caused by a bug.
252 guarantee(min_bytes <= max_jint, "we dont support archiving more than 2G of objects");
253 _buffer->at_grow(to_array_index(min_bytes));
254 }
255
256 objArrayOop AOTMappedHeapWriter::allocate_root_segment(size_t offset, int element_count) {
257 HeapWord* mem = offset_to_buffered_address<HeapWord *>(offset);
258 memset(mem, 0, objArrayOopDesc::object_size(element_count));
259
260 // The initialization code is copied from MemAllocator::finish and ObjArrayAllocator::initialize.
261 if (UseCompactObjectHeaders) {
262 oopDesc::release_set_mark(mem, Universe::objectArrayKlass()->prototype_header());
263 } else {
264 oopDesc::set_mark(mem, markWord::prototype());
265 oopDesc::release_set_klass(mem, Universe::objectArrayKlass());
266 }
267 arrayOopDesc::set_length(mem, element_count);
268 return objArrayOop(cast_to_oop(mem));
269 }
270
271 void AOTMappedHeapWriter::root_segment_at_put(objArrayOop segment, int index, oop root) {
272 // Do not use arrayOop->obj_at_put(i, o) as arrayOop is outside the real heap!
273 if (UseCompressedOops) {
274 *segment->obj_at_addr<narrowOop>(index) = CompressedOops::encode(root);
275 } else {
276 *segment->obj_at_addr<oop>(index) = root;
277 }
278 }
279
280 void AOTMappedHeapWriter::copy_roots_to_buffer(GrowableArrayCHeap<oop, mtClassShared>* roots) {
281 // Depending on the number of classes we are archiving, a single roots array may be
282 // larger than MIN_GC_REGION_ALIGNMENT. Roots are allocated first in the buffer, which
283 // allows us to chop the large array into a series of "segments". Current layout
284 // starts with zero or more segments exactly fitting MIN_GC_REGION_ALIGNMENT, and end
285 // with a single segment that may be smaller than MIN_GC_REGION_ALIGNMENT.
286 // This is simple and efficient. We do not need filler objects anywhere between the segments,
287 // or immediately after the last segment. This allows starting the object dump immediately
288 // after the roots.
289
290 assert((_buffer_used % MIN_GC_REGION_ALIGNMENT) == 0,
291 "Pre-condition: Roots start at aligned boundary: %zu", _buffer_used);
292
293 int max_elem_count = ((MIN_GC_REGION_ALIGNMENT - arrayOopDesc::header_size_in_bytes()) / heapOopSize);
294 assert(objArrayOopDesc::object_size(max_elem_count)*HeapWordSize == MIN_GC_REGION_ALIGNMENT,
295 "Should match exactly");
296
297 HeapRootSegments segments(_buffer_used,
298 roots->length(),
299 MIN_GC_REGION_ALIGNMENT,
300 max_elem_count);
301
302 int root_index = 0;
303 for (size_t seg_idx = 0; seg_idx < segments.count(); seg_idx++) {
304 int size_elems = segments.size_in_elems(seg_idx);
305 size_t size_bytes = segments.size_in_bytes(seg_idx);
306
307 size_t oop_offset = _buffer_used;
308 _buffer_used = oop_offset + size_bytes;
309 ensure_buffer_space(_buffer_used);
310
311 assert((oop_offset % MIN_GC_REGION_ALIGNMENT) == 0,
312 "Roots segment %zu start is not aligned: %zu",
313 segments.count(), oop_offset);
314
315 objArrayOop seg_oop = allocate_root_segment(oop_offset, size_elems);
316 for (int i = 0; i < size_elems; i++) {
317 root_segment_at_put(seg_oop, i, roots->at(root_index++));
318 }
319
320 log_info(aot, heap)("archived obj root segment [%d] = %zu bytes, obj = " PTR_FORMAT,
321 size_elems, size_bytes, p2i(seg_oop));
322 }
323
324 assert(root_index == roots->length(), "Post-condition: All roots are handled");
325
326 _heap_root_segments = segments;
327 }
328
329 // The goal is to sort the objects in increasing order of:
330 // - objects that have only oop pointers
331 // - objects that have both native and oop pointers
332 // - objects that have only native pointers
333 // - objects that have no pointers
334 static int oop_sorting_rank(oop o) {
335 bool has_oop_ptr, has_native_ptr;
336 HeapShared::get_pointer_info(o, has_oop_ptr, has_native_ptr);
337
338 if (has_oop_ptr) {
339 if (!has_native_ptr) {
340 return 0;
341 } else {
342 return 1;
343 }
344 } else {
345 if (has_native_ptr) {
346 return 2;
347 } else {
348 return 3;
349 }
350 }
351 }
352
353 int AOTMappedHeapWriter::compare_objs_by_oop_fields(HeapObjOrder* a, HeapObjOrder* b) {
354 int rank_a = a->_rank;
355 int rank_b = b->_rank;
356
357 if (rank_a != rank_b) {
358 return rank_a - rank_b;
359 } else {
360 // If they are the same rank, sort them by their position in the _source_objs array
361 return a->_index - b->_index;
362 }
363 }
364
365 void AOTMappedHeapWriter::sort_source_objs() {
366 log_info(aot)("sorting heap objects");
367 int len = _source_objs->length();
368 _source_objs_order = new GrowableArrayCHeap<HeapObjOrder, mtClassShared>(len);
369
370 for (int i = 0; i < len; i++) {
371 oop o = _source_objs->at(i);
372 int rank = oop_sorting_rank(o);
373 HeapObjOrder os = {i, rank};
374 _source_objs_order->append(os);
375 }
376 log_info(aot)("computed ranks");
377 _source_objs_order->sort(compare_objs_by_oop_fields);
378 log_info(aot)("sorting heap objects done");
379 }
380
381 void AOTMappedHeapWriter::copy_source_objs_to_buffer(GrowableArrayCHeap<oop, mtClassShared>* roots) {
382 // There could be multiple root segments, which we want to be aligned by region.
383 // Putting them ahead of objects makes sure we waste no space.
384 copy_roots_to_buffer(roots);
385
386 sort_source_objs();
387 for (int i = 0; i < _source_objs_order->length(); i++) {
388 int src_obj_index = _source_objs_order->at(i)._index;
389 oop src_obj = _source_objs->at(src_obj_index);
390 HeapShared::CachedOopInfo* info = HeapShared::get_cached_oop_info(src_obj);
391 assert(info != nullptr, "must be");
392 size_t buffer_offset = copy_one_source_obj_to_buffer(src_obj);
393 info->set_buffer_offset(buffer_offset);
394
395 OopHandle handle(Universe::vm_global(), src_obj);
396 _buffer_offset_to_source_obj_table->put_when_absent(buffer_offset, handle);
397 _buffer_offset_to_source_obj_table->maybe_grow();
398
399 if (java_lang_Module::is_instance(src_obj)) {
400 Modules::check_archived_module_oop(src_obj);
401 }
402 }
403
404 log_info(aot)("Size of heap region = %zu bytes, %d objects, %d roots, %d native ptrs",
405 _buffer_used, _source_objs->length() + 1, roots->length(), _num_native_ptrs);
406 }
407
408 size_t AOTMappedHeapWriter::filler_array_byte_size(int length) {
409 size_t byte_size = objArrayOopDesc::object_size(length) * HeapWordSize;
410 return byte_size;
411 }
412
413 int AOTMappedHeapWriter::filler_array_length(size_t fill_bytes) {
414 assert(is_object_aligned(fill_bytes), "must be");
415 size_t elemSize = (UseCompressedOops ? sizeof(narrowOop) : sizeof(oop));
416
417 int initial_length = to_array_length(fill_bytes / elemSize);
418 for (int length = initial_length; length >= 0; length --) {
419 size_t array_byte_size = filler_array_byte_size(length);
420 if (array_byte_size == fill_bytes) {
421 return length;
422 }
423 }
424
425 ShouldNotReachHere();
426 return -1;
427 }
428
429 HeapWord* AOTMappedHeapWriter::init_filler_array_at_buffer_top(int array_length, size_t fill_bytes) {
430 assert(UseCompressedClassPointers, "Archived heap only supported for compressed klasses");
431 Klass* oak = Universe::objectArrayKlass(); // already relocated to point to archived klass
432 HeapWord* mem = offset_to_buffered_address<HeapWord*>(_buffer_used);
433 memset(mem, 0, fill_bytes);
434 narrowKlass nk = ArchiveBuilder::current()->get_requested_narrow_klass(oak);
435 if (UseCompactObjectHeaders) {
436 oopDesc::release_set_mark(mem, markWord::prototype().set_narrow_klass(nk));
437 } else {
438 oopDesc::set_mark(mem, markWord::prototype());
439 cast_to_oop(mem)->set_narrow_klass(nk);
440 }
441 arrayOopDesc::set_length(mem, array_length);
442 return mem;
443 }
444
445 void AOTMappedHeapWriter::maybe_fill_gc_region_gap(size_t required_byte_size) {
446 // We fill only with arrays (so we don't need to use a single HeapWord filler if the
447 // leftover space is smaller than a zero-sized array object). Therefore, we need to
448 // make sure there's enough space of min_filler_byte_size in the current region after
449 // required_byte_size has been allocated. If not, fill the remainder of the current
450 // region.
451 size_t min_filler_byte_size = filler_array_byte_size(0);
452 size_t new_used = _buffer_used + required_byte_size + min_filler_byte_size;
453
454 const size_t cur_min_region_bottom = align_down(_buffer_used, MIN_GC_REGION_ALIGNMENT);
455 const size_t next_min_region_bottom = align_down(new_used, MIN_GC_REGION_ALIGNMENT);
456
457 if (cur_min_region_bottom != next_min_region_bottom) {
458 // Make sure that no objects span across MIN_GC_REGION_ALIGNMENT. This way
459 // we can map the region in any region-based collector.
460 assert(next_min_region_bottom > cur_min_region_bottom, "must be");
461 assert(next_min_region_bottom - cur_min_region_bottom == MIN_GC_REGION_ALIGNMENT,
462 "no buffered object can be larger than %d bytes", MIN_GC_REGION_ALIGNMENT);
463
464 const size_t filler_end = next_min_region_bottom;
465 const size_t fill_bytes = filler_end - _buffer_used;
466 assert(fill_bytes > 0, "must be");
467 ensure_buffer_space(filler_end);
468
469 int array_length = filler_array_length(fill_bytes);
470 log_info(aot, heap)("Inserting filler obj array of %d elements (%zu bytes total) @ buffer offset %zu",
471 array_length, fill_bytes, _buffer_used);
472 HeapWord* filler = init_filler_array_at_buffer_top(array_length, fill_bytes);
473 _buffer_used = filler_end;
474 _fillers->put(buffered_address_to_offset((address)filler), fill_bytes);
475 }
476 }
477
478 size_t AOTMappedHeapWriter::get_filler_size_at(address buffered_addr) {
479 size_t* p = _fillers->get(buffered_address_to_offset(buffered_addr));
480 if (p != nullptr) {
481 assert(*p > 0, "filler must be larger than zero bytes");
482 return *p;
483 } else {
484 return 0; // buffered_addr is not a filler
485 }
486 }
487
488 template <typename T>
489 void update_buffered_object_field(address buffered_obj, int field_offset, T value) {
490 T* field_addr = cast_to_oop(buffered_obj)->field_addr<T>(field_offset);
491 *field_addr = value;
492 }
493
494 size_t AOTMappedHeapWriter::copy_one_source_obj_to_buffer(oop src_obj) {
495 assert(!is_too_large_to_archive(src_obj), "already checked");
496 size_t byte_size = src_obj->size() * HeapWordSize;
497 assert(byte_size > 0, "no zero-size objects");
498
499 // For region-based collectors such as G1, the archive heap may be mapped into
500 // multiple regions. We need to make sure that we don't have an object that can possible
501 // span across two regions.
502 maybe_fill_gc_region_gap(byte_size);
503
504 size_t new_used = _buffer_used + byte_size;
505 assert(new_used > _buffer_used, "no wrap around");
506
507 size_t cur_min_region_bottom = align_down(_buffer_used, MIN_GC_REGION_ALIGNMENT);
508 size_t next_min_region_bottom = align_down(new_used, MIN_GC_REGION_ALIGNMENT);
509 assert(cur_min_region_bottom == next_min_region_bottom, "no object should cross minimal GC region boundaries");
510
511 ensure_buffer_space(new_used);
512
513 address from = cast_from_oop<address>(src_obj);
514 address to = offset_to_buffered_address<address>(_buffer_used);
515 assert(is_object_aligned(_buffer_used), "sanity");
516 assert(is_object_aligned(byte_size), "sanity");
517 memcpy(to, from, byte_size);
518
519 // These native pointers will be restored explicitly at run time.
520 if (java_lang_Module::is_instance(src_obj)) {
521 update_buffered_object_field<ModuleEntry*>(to, java_lang_Module::module_entry_offset(), nullptr);
522 } else if (java_lang_ClassLoader::is_instance(src_obj)) {
523 #ifdef ASSERT
524 // We only archive these loaders
525 if (src_obj != SystemDictionary::java_platform_loader() &&
526 src_obj != SystemDictionary::java_system_loader()) {
527 assert(src_obj->klass()->name()->equals("jdk/internal/loader/ClassLoaders$BootClassLoader"), "must be");
528 }
529 #endif
530 update_buffered_object_field<ClassLoaderData*>(to, java_lang_ClassLoader::loader_data_offset(), nullptr);
531 }
532
533 size_t buffered_obj_offset = _buffer_used;
534 _buffer_used = new_used;
535
536 return buffered_obj_offset;
537 }
538
539 void AOTMappedHeapWriter::set_requested_address(ArchiveMappedHeapInfo* info) {
540 assert(!info->is_used(), "only set once");
541
542 size_t heap_region_byte_size = _buffer_used;
543 assert(heap_region_byte_size > 0, "must archived at least one object!");
544
545 if (UseCompressedOops) {
546 if (UseG1GC) {
547 address heap_end = (address)G1CollectedHeap::heap()->reserved().end();
548 log_info(aot, heap)("Heap end = %p", heap_end);
549 _requested_bottom = align_down(heap_end - heap_region_byte_size, G1HeapRegion::GrainBytes);
550 _requested_bottom = align_down(_requested_bottom, MIN_GC_REGION_ALIGNMENT);
551 assert(is_aligned(_requested_bottom, G1HeapRegion::GrainBytes), "sanity");
552 } else {
553 _requested_bottom = align_up(CompressedOops::begin(), MIN_GC_REGION_ALIGNMENT);
554 }
555 } else {
556 // We always write the objects as if the heap started at this address. This
557 // makes the contents of the archive heap deterministic.
558 //
559 // Note that at runtime, the heap address is selected by the OS, so the archive
560 // heap will not be mapped at 0x10000000, and the contents need to be patched.
561 _requested_bottom = align_up((address)NOCOOPS_REQUESTED_BASE, MIN_GC_REGION_ALIGNMENT);
562 }
563
564 assert(is_aligned(_requested_bottom, MIN_GC_REGION_ALIGNMENT), "sanity");
565
566 _requested_top = _requested_bottom + _buffer_used;
567
568 info->set_buffer_region(MemRegion(offset_to_buffered_address<HeapWord*>(0),
569 offset_to_buffered_address<HeapWord*>(_buffer_used)));
570 info->set_root_segments(_heap_root_segments);
571 }
572
573 // Oop relocation
574
575 template <typename T> T* AOTMappedHeapWriter::requested_addr_to_buffered_addr(T* p) {
576 assert(is_in_requested_range(cast_to_oop(p)), "must be");
577
578 address addr = address(p);
579 assert(addr >= _requested_bottom, "must be");
580 size_t offset = addr - _requested_bottom;
581 return offset_to_buffered_address<T*>(offset);
582 }
583
584 template <typename T> oop AOTMappedHeapWriter::load_source_oop_from_buffer(T* buffered_addr) {
585 oop o = load_oop_from_buffer(buffered_addr);
586 assert(!in_buffer(cast_from_oop<address>(o)), "must point to source oop");
587 return o;
588 }
589
590 template <typename T> void AOTMappedHeapWriter::store_requested_oop_in_buffer(T* buffered_addr,
591 oop request_oop) {
592 assert(request_oop == nullptr || is_in_requested_range(request_oop), "must be");
593 store_oop_in_buffer(buffered_addr, request_oop);
594 }
595
596 inline void AOTMappedHeapWriter::store_oop_in_buffer(oop* buffered_addr, oop requested_obj) {
597 *buffered_addr = requested_obj;
598 }
599
600 inline void AOTMappedHeapWriter::store_oop_in_buffer(narrowOop* buffered_addr, oop requested_obj) {
601 narrowOop val = CompressedOops::encode(requested_obj);
602 *buffered_addr = val;
603 }
604
605 oop AOTMappedHeapWriter::load_oop_from_buffer(oop* buffered_addr) {
606 return *buffered_addr;
607 }
608
609 oop AOTMappedHeapWriter::load_oop_from_buffer(narrowOop* buffered_addr) {
610 return CompressedOops::decode(*buffered_addr);
611 }
612
613 template <typename T> void AOTMappedHeapWriter::relocate_field_in_buffer(T* field_addr_in_buffer, oop source_referent, CHeapBitMap* oopmap) {
614 oop request_referent = source_obj_to_requested_obj(source_referent);
615 store_requested_oop_in_buffer<T>(field_addr_in_buffer, request_referent);
616 if (request_referent != nullptr) {
617 mark_oop_pointer<T>(field_addr_in_buffer, oopmap);
618 }
619 }
620
621 template <typename T> void AOTMappedHeapWriter::mark_oop_pointer(T* buffered_addr, CHeapBitMap* oopmap) {
622 T* request_p = (T*)(buffered_addr_to_requested_addr((address)buffered_addr));
623 address requested_region_bottom;
624
625 assert(request_p >= (T*)_requested_bottom, "sanity");
626 assert(request_p < (T*)_requested_top, "sanity");
627 requested_region_bottom = _requested_bottom;
628
629 // Mark the pointer in the oopmap
630 T* region_bottom = (T*)requested_region_bottom;
631 assert(request_p >= region_bottom, "must be");
632 BitMap::idx_t idx = request_p - region_bottom;
633 assert(idx < oopmap->size(), "overflow");
634 oopmap->set_bit(idx);
635 }
636
637 void AOTMappedHeapWriter::update_header_for_requested_obj(oop requested_obj, oop src_obj, Klass* src_klass) {
638 assert(UseCompressedClassPointers, "Archived heap only supported for compressed klasses");
639 narrowKlass nk = ArchiveBuilder::current()->get_requested_narrow_klass(src_klass);
640 address buffered_addr = requested_addr_to_buffered_addr(cast_from_oop<address>(requested_obj));
641
642 oop fake_oop = cast_to_oop(buffered_addr);
643 if (UseCompactObjectHeaders) {
644 fake_oop->set_mark(markWord::prototype().set_narrow_klass(nk));
645 } else {
646 fake_oop->set_narrow_klass(nk);
647 }
648
649 if (src_obj == nullptr) {
650 return;
651 }
652 // We need to retain the identity_hash, because it may have been used by some hashtables
653 // in the shared heap.
654 if (!src_obj->fast_no_hash_check()) {
655 intptr_t src_hash = src_obj->identity_hash();
656 if (UseCompactObjectHeaders) {
657 fake_oop->set_mark(markWord::prototype().set_narrow_klass(nk).copy_set_hash(src_hash));
658 } else {
659 fake_oop->set_mark(markWord::prototype().copy_set_hash(src_hash));
660 }
661 assert(fake_oop->mark().is_unlocked(), "sanity");
662
663 DEBUG_ONLY(intptr_t archived_hash = fake_oop->identity_hash());
664 assert(src_hash == archived_hash, "Different hash codes: original " INTPTR_FORMAT ", archived " INTPTR_FORMAT, src_hash, archived_hash);
665 }
666 // Strip age bits.
667 fake_oop->set_mark(fake_oop->mark().set_age(0));
668 }
669
670 class AOTMappedHeapWriter::EmbeddedOopRelocator: public BasicOopIterateClosure {
671 oop _src_obj;
672 address _buffered_obj;
673 CHeapBitMap* _oopmap;
674 bool _is_java_lang_ref;
675 public:
676 EmbeddedOopRelocator(oop src_obj, address buffered_obj, CHeapBitMap* oopmap) :
677 _src_obj(src_obj), _buffered_obj(buffered_obj), _oopmap(oopmap)
678 {
679 _is_java_lang_ref = AOTReferenceObjSupport::check_if_ref_obj(src_obj);
680 }
681
682 void do_oop(narrowOop *p) { EmbeddedOopRelocator::do_oop_work(p); }
683 void do_oop( oop *p) { EmbeddedOopRelocator::do_oop_work(p); }
684
685 private:
686 template <class T> void do_oop_work(T *p) {
687 int field_offset = pointer_delta_as_int((char*)p, cast_from_oop<char*>(_src_obj));
688 T* field_addr = (T*)(_buffered_obj + field_offset);
689 oop referent = load_source_oop_from_buffer<T>(field_addr);
690 referent = HeapShared::maybe_remap_referent(_is_java_lang_ref, field_offset, referent);
691 AOTMappedHeapWriter::relocate_field_in_buffer<T>(field_addr, referent, _oopmap);
692 }
693 };
694
695 static void log_bitmap_usage(const char* which, BitMap* bitmap, size_t total_bits) {
696 // The whole heap is covered by total_bits, but there are only non-zero bits within [start ... end).
697 size_t start = bitmap->find_first_set_bit(0);
698 size_t end = bitmap->size();
699 log_info(aot)("%s = %7zu ... %7zu (%3zu%% ... %3zu%% = %3zu%%)", which,
700 start, end,
701 start * 100 / total_bits,
702 end * 100 / total_bits,
703 (end - start) * 100 / total_bits);
704 }
705
706 // Update all oop fields embedded in the buffered objects
707 void AOTMappedHeapWriter::relocate_embedded_oops(GrowableArrayCHeap<oop, mtClassShared>* roots,
708 ArchiveMappedHeapInfo* heap_info) {
709 size_t oopmap_unit = (UseCompressedOops ? sizeof(narrowOop) : sizeof(oop));
710 size_t heap_region_byte_size = _buffer_used;
711 heap_info->oopmap()->resize(heap_region_byte_size / oopmap_unit);
712
713 for (int i = 0; i < _source_objs_order->length(); i++) {
714 int src_obj_index = _source_objs_order->at(i)._index;
715 oop src_obj = _source_objs->at(src_obj_index);
716 HeapShared::CachedOopInfo* info = HeapShared::get_cached_oop_info(src_obj);
717 assert(info != nullptr, "must be");
718 oop requested_obj = requested_obj_from_buffer_offset(info->buffer_offset());
719 update_header_for_requested_obj(requested_obj, src_obj, src_obj->klass());
720 address buffered_obj = offset_to_buffered_address<address>(info->buffer_offset());
721 EmbeddedOopRelocator relocator(src_obj, buffered_obj, heap_info->oopmap());
722 src_obj->oop_iterate(&relocator);
723 mark_native_pointers(src_obj);
724 };
725
726 // Relocate HeapShared::roots(), which is created in copy_roots_to_buffer() and
727 // doesn't have a corresponding src_obj, so we can't use EmbeddedOopRelocator on it.
728 for (size_t seg_idx = 0; seg_idx < _heap_root_segments.count(); seg_idx++) {
729 size_t seg_offset = _heap_root_segments.segment_offset(seg_idx);
730
731 objArrayOop requested_obj = (objArrayOop)requested_obj_from_buffer_offset(seg_offset);
732 update_header_for_requested_obj(requested_obj, nullptr, Universe::objectArrayKlass());
733 address buffered_obj = offset_to_buffered_address<address>(seg_offset);
734 int length = _heap_root_segments.size_in_elems(seg_idx);
735
736 size_t elem_size = UseCompressedOops ? sizeof(narrowOop) : sizeof(oop);
737
738 for (int i = 0; i < length; i++) {
739 // There is no source object; these are native oops - load, translate and
740 // write back
741 size_t elem_offset = objArrayOopDesc::base_offset_in_bytes() + elem_size * i;
742 HeapWord* elem_addr = (HeapWord*)(buffered_obj + elem_offset);
743 oop obj = NativeAccess<>::oop_load(elem_addr);
744 obj = HeapShared::maybe_remap_referent(false /* is_reference_field */, elem_offset, obj);
745 if (UseCompressedOops) {
746 relocate_field_in_buffer<narrowOop>((narrowOop*)elem_addr, obj, heap_info->oopmap());
747 } else {
748 relocate_field_in_buffer<oop>((oop*)elem_addr, obj, heap_info->oopmap());
749 }
750 }
751 }
752
753 compute_ptrmap(heap_info);
754
755 size_t total_bytes = (size_t)_buffer->length();
756 log_bitmap_usage("oopmap", heap_info->oopmap(), total_bytes / (UseCompressedOops ? sizeof(narrowOop) : sizeof(oop)));
757 log_bitmap_usage("ptrmap", heap_info->ptrmap(), total_bytes / sizeof(address));
758 }
759
760 void AOTMappedHeapWriter::mark_native_pointer(oop src_obj, int field_offset) {
761 Metadata* ptr = src_obj->metadata_field_acquire(field_offset);
762 if (ptr != nullptr) {
763 NativePointerInfo info;
764 info._src_obj = src_obj;
765 info._field_offset = field_offset;
766 _native_pointers->append(info);
767 HeapShared::set_has_native_pointers(src_obj);
768 _num_native_ptrs ++;
769 }
770 }
771
772 void AOTMappedHeapWriter::mark_native_pointers(oop orig_obj) {
773 HeapShared::do_metadata_offsets(orig_obj, [&](int offset) {
774 mark_native_pointer(orig_obj, offset);
775 });
776 }
777
778 void AOTMappedHeapWriter::compute_ptrmap(ArchiveMappedHeapInfo* heap_info) {
779 int num_non_null_ptrs = 0;
780 Metadata** bottom = (Metadata**) _requested_bottom;
781 Metadata** top = (Metadata**) _requested_top; // exclusive
782 heap_info->ptrmap()->resize(top - bottom);
783
784 BitMap::idx_t max_idx = 32; // paranoid - don't make it too small
785 for (int i = 0; i < _native_pointers->length(); i++) {
786 NativePointerInfo info = _native_pointers->at(i);
787 oop src_obj = info._src_obj;
788 int field_offset = info._field_offset;
789 HeapShared::CachedOopInfo* p = HeapShared::get_cached_oop_info(src_obj);
790 // requested_field_addr = the address of this field in the requested space
791 oop requested_obj = requested_obj_from_buffer_offset(p->buffer_offset());
792 Metadata** requested_field_addr = (Metadata**)(cast_from_oop<address>(requested_obj) + field_offset);
793 assert(bottom <= requested_field_addr && requested_field_addr < top, "range check");
794
795 // Mark this field in the bitmap
796 BitMap::idx_t idx = requested_field_addr - bottom;
797 heap_info->ptrmap()->set_bit(idx);
798 num_non_null_ptrs ++;
799 max_idx = MAX2(max_idx, idx);
800
801 // Set the native pointer to the requested address of the metadata (at runtime, the metadata will have
802 // this address if the RO/RW regions are mapped at the default location).
803
804 Metadata** buffered_field_addr = requested_addr_to_buffered_addr(requested_field_addr);
805 Metadata* native_ptr = *buffered_field_addr;
806 guarantee(native_ptr != nullptr, "sanity");
807
808 if (RegeneratedClasses::has_been_regenerated(native_ptr)) {
809 native_ptr = RegeneratedClasses::get_regenerated_object(native_ptr);
810 }
811
812 guarantee(ArchiveBuilder::current()->has_been_archived((address)native_ptr),
813 "Metadata %p should have been archived", native_ptr);
814
815 address buffered_native_ptr = ArchiveBuilder::current()->get_buffered_addr((address)native_ptr);
816 address requested_native_ptr = ArchiveBuilder::current()->to_requested(buffered_native_ptr);
817 *buffered_field_addr = (Metadata*)requested_native_ptr;
818 }
819
820 heap_info->ptrmap()->resize(max_idx + 1);
821 log_info(aot, heap)("calculate_ptrmap: marked %d non-null native pointers for heap region (%zu bits)",
822 num_non_null_ptrs, size_t(heap_info->ptrmap()->size()));
823 }
824
825 AOTMapLogger::OopDataIterator* AOTMappedHeapWriter::oop_iterator(ArchiveMappedHeapInfo* heap_info) {
826 class MappedWriterOopIterator : public AOTMapLogger::OopDataIterator {
827 private:
828 address _current;
829 address _next;
830
831 address _buffer_start;
832 address _buffer_end;
833 uint64_t _buffer_start_narrow_oop;
834 intptr_t _buffer_to_requested_delta;
835 int _requested_shift;
836
837 size_t _num_root_segments;
838 size_t _num_obj_arrays_logged;
839
840 public:
841 MappedWriterOopIterator(address buffer_start,
842 address buffer_end,
843 uint64_t buffer_start_narrow_oop,
844 intptr_t buffer_to_requested_delta,
845 int requested_shift,
846 size_t num_root_segments)
847 : _current(nullptr),
848 _next(buffer_start),
849 _buffer_start(buffer_start),
850 _buffer_end(buffer_end),
851 _buffer_start_narrow_oop(buffer_start_narrow_oop),
852 _buffer_to_requested_delta(buffer_to_requested_delta),
853 _requested_shift(requested_shift),
854 _num_root_segments(num_root_segments),
855 _num_obj_arrays_logged(0) {
856 }
857
858 AOTMapLogger::OopData capture(address buffered_addr) {
859 oopDesc* raw_oop = (oopDesc*)buffered_addr;
860 size_t size = size_of_buffered_oop(buffered_addr);
861 address requested_addr = buffered_addr_to_requested_addr(buffered_addr);
862 intptr_t target_location = (intptr_t)requested_addr;
863 uint64_t pd = (uint64_t)(pointer_delta(buffered_addr, _buffer_start, 1));
864 uint32_t narrow_location = checked_cast<uint32_t>(_buffer_start_narrow_oop + (pd >> _requested_shift));
865 Klass* klass = real_klass_of_buffered_oop(buffered_addr);
866
867 return { buffered_addr,
868 requested_addr,
869 target_location,
870 narrow_location,
871 raw_oop,
872 klass,
873 size,
874 false };
875 }
876
877 bool has_next() override {
878 return _next < _buffer_end;
879 }
880
881 AOTMapLogger::OopData next() override {
882 _current = _next;
883 AOTMapLogger::OopData result = capture(_current);
884 if (result._klass->is_objArray_klass()) {
885 result._is_root_segment = _num_obj_arrays_logged++ < _num_root_segments;
886 }
887 _next = _current + result._size * BytesPerWord;
888 return result;
889 }
890
891 AOTMapLogger::OopData obj_at(narrowOop* addr) override {
892 uint64_t n = (uint64_t)(*addr);
893 if (n == 0) {
894 return null_data();
895 } else {
896 precond(n >= _buffer_start_narrow_oop);
897 address buffer_addr = _buffer_start + ((n - _buffer_start_narrow_oop) << _requested_shift);
898 return capture(buffer_addr);
899 }
900 }
901
902 AOTMapLogger::OopData obj_at(oop* addr) override {
903 address requested_value = cast_from_oop<address>(*addr);
904 if (requested_value == nullptr) {
905 return null_data();
906 } else {
907 address buffer_addr = requested_value - _buffer_to_requested_delta;
908 return capture(buffer_addr);
909 }
910 }
911
912 GrowableArrayCHeap<AOTMapLogger::OopData, mtClass>* roots() override {
913 return new GrowableArrayCHeap<AOTMapLogger::OopData, mtClass>();
914 }
915 };
916
917 MemRegion r = heap_info->buffer_region();
918 address buffer_start = address(r.start());
919 address buffer_end = address(r.end());
920
921 address requested_base = UseCompressedOops ? (address)CompressedOops::base() : (address)AOTMappedHeapWriter::NOCOOPS_REQUESTED_BASE;
922 address requested_start = UseCompressedOops ? buffered_addr_to_requested_addr(buffer_start) : requested_base;
923 int requested_shift = CompressedOops::shift();
924 intptr_t buffer_to_requested_delta = requested_start - buffer_start;
925 uint64_t buffer_start_narrow_oop = 0xdeadbeed;
926 if (UseCompressedOops) {
927 buffer_start_narrow_oop = (uint64_t)(pointer_delta(requested_start, requested_base, 1)) >> requested_shift;
928 assert(buffer_start_narrow_oop < 0xffffffff, "sanity");
929 }
930
931 return new MappedWriterOopIterator(buffer_start,
932 buffer_end,
933 buffer_start_narrow_oop,
934 buffer_to_requested_delta,
935 requested_shift,
936 heap_info->root_segments().count());
937 }
938
939 #endif // INCLUDE_CDS_JAVA_HEAP